The present disclosure relates generally to the manufacture of fused glass tubing, and, more particularly, to fused glass tubing formed from an overflow process.
During glass forming, when surfaces are touched by tooling, as is typical in current fabrication methods, the surface becomes damaged. When viewed by the unaided eye, these damages are visible as optical distortions. Additionally, these defects are easily viewed as dark lines when observed via Xenon shadowgraph. Damaged surfaces are undesirable for applications which require the highest optical quality, similar to that which is achieved with fusion-formed glass. In addition, defects caused by tooling can decrease the strength and reliability of a tube.